Affiliations: Department of Dental Materials, College of Dentistry and Institute for Biomaterials Research and Development, Kyungpook National University, Taegu, Korea | Instrumentation System Lab, Korea Research Institute of Standards and Science, Taejon, Korea | Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan
Note: [] Corresponding author: Mr Kyo-Han Kim, 2-101, Dongin-Dong, Jung-Gu, Taegu 700-422, Korea. Tel.: 82-53-420-6821; Fax: 82-53-422-9631; E-mail: kyohan@bh.kyungpook.ac.kr.
Abstract: The fracture behavior of cast two types of pure Ti and Ti-6A1-4V alloy was understood by acoustic emission (AE) analysis during a fracture toughness test. Specimens for test were cast by the lost wax method using a specially designed Ti casting machine of pressure-different method for dental use. A fatigue crack was inserted from the machined notch tip into the body of a specimen in the range of 0.45–0.55 a/W. Acoustic emission signals released during the fracture toughness test were detected by two sensors attached to both ends of the specimen. Then the signals were recorded and analysed by the PAC 3000/3104 system. From the early stage of the fracture toughness test, AE signals started to be released in all types of specimens tested. A reaction layer with the investment materials of about 50–100 μm was thought to be the result of the AE release from an early stage of the fracture toughness test. A microfracture behavior of the cast pure Ti and Ti alloys was proposed based on the results obtained from the AE releasing pattern and fracture surface findings.
Keywords: Pure Ti, Ti-6A1-4V alloy, fracture toughness, acoustic emission (AE)
